The growth of Microcystis with amino acids as nitrogen source

A method was devised for the exclusion of nitrogen and nitrogenous compounds from precultures that were used for inculation of blue green algae. The growth rate of the blue green algae was not altered by this procedure. The influence of different nitrogen sources on the growth of M. UV-007 could then be studied in such a way that no nitrogen could be introduced by the inoculum. Results of experiments where nitrate nitrogen was supplied show that there is a linear relationship between turbidity and nitrate nitrogen used. Results of experiments on the utilization of different amino acids as only source of nitrogen are given. Experiments were also devised to ascertain whether the amino acids not used as nitrogen source were taken up by M. UV-007 cultures. For the experiments 14C-amino acids were used. During the study of the utilization of different amino acid nitrogen sources by M. UV-007, granules of cyanophycine were found in cultures which contained L-arginine, L-citrulline and L-asparagine as sole nitrogen sources. Of all the inoranic nitrogen sources and urea used by M. UV-007, nitrate nitrogen was utilized best. L-Arginine was the best utilized amino acid by M. UV-007 and L-alanine was the best utilized by M. UV-006 as amino acid nitrogen source